Hello!

I have a problem on my NS Oscar 2, there is some noise coming from the machine and as you can see on the video following this link, some vapor/boiling water goes out

What's the problem and what should I do?

http://www.vimeo.com/459710639

Many thanks!!

That's the anti-vacuum valve spurting out water. The only time you should see any water coming out of it is after you first turn on the machine and the boiler is heating up. In this case, it's normal for a little water to be coming from the valve, but should only last for about 5 - 10 minutes. Once boiler pressure is sufficient, the pressure will push the valve closed and you should see no more leaks. If the valve is leaking after the machine has completely warmed up, then the vavle o-ring is probably bad.

I don't own an Oscar, but this type valve is used on many machines. While the valve in the linked thread is a little different, it does the same job. You can use the thread to give you an idea of what the valve looks like. Your valve may be a built differently, but will probably have a relaceable o-ring inside. You could replace the entire valve, but many just disassemble it, clean it, and change the o-ring. If you're able to change the o-ring, you have to use one that's high temp... a regular plumbing o-ring used for house plumbing won't work.

Quick Mill Anita vacuum breaker valve problem? [solved]

I'm sure someone here has done an o-ring replacement on an Oscar... you might use the Search function at the top to try to locate a thread.

+1 for Nahau's post

the simplest fix, pull up the center, twist right then left.




If that doesn't work, support the fixture below and use a 19mm socket to remove.
carefully remove the clip, inspect o-ring and nylon seat.

troubleshooting&parts

HTH